This invention relates to a process of producing pre-oriented continuous yarns from synthetic thermoplastics by a melt-spinning of monofilaments, which are subsequently taken off, cooled and wound up without use of a godet roll and at velocities of more than 2500 meters per minute.
Spinning processes are known in which godet rolls rotating virtually at the take-off velocity are used as deflecting means. In the spin-stretching process, the filament is stretched in a hot or cold condition between two godet rolls or two pairs of godet rolls and at take-off velocities up to about 4000 meters per minute. The use of godet rolls results in frequent trouble during operation so that the spinning process is interrupted and production is lost. Where hot godet rolls are used, they must be heated to relatively high temperatures so that additional costs are incurred.
High-speed spinning processes obviously involve higher requirements as regards the precision of the means which participate in the formation of the yarn and as regards the process conditions.
The resulting yarns should have uniform good physical properties and should be such as to enable a further processing with a minimum of trouble. This will particularly depend on the compacting properties of the filaments, on the formation of a uniform coating balanced moisture absorption and desorption, the formation of a uniform package without floofs and loops, etc.